1. Field of the Invention
The present invention relates to mobile golf practice devices which assist golfers in improving the accuracy of their stroke; and, more particularly, to a vehicle mounted device which allows a golfer to observe the correctness of his swing.
2. Description of the Related Art
Golf has become a national pastime. The paraphernalia that is available to the golfer is second to none. Although golf is very popular, and does not require a great deal of physical endurance, it is nevertheless a game of skill. Therefore, a number of devices have been offered to improve the golfer""s swing, as well as his contact with the ball. For example, ergonomic putters are designed with the shaft attached to the head in the center of club, rather than at the end. Resin and graphite have replaced the old metal shaft. Adjustable club heads actually allow the golfer to adjust the head angle to correct for a slice or hook.
No matter how sophisticated the equipment gets, the fact of the matter is that a player""s score is impacted most greatly by his swing and thus the way in which he addresses and strikes the golf ball. Therefore, many golf practice devices have been designed to allow stance and stroke practice at locations other than the golf course or the driving range. Some of these practice devices involve computerized imagery which use complicated software to simulate the path of the ball after it is hit. These are expensive and bulky. Others are more simple in design and attach to stationary objects or are attached to bases adapted to be driven into the ground. These devices incorporate, for example wiffle balls (hollow balls with holes in the surface), as well as actual golf balls that are tethered to extensions or arms such that they can be hit without having the golfer chase or otherwise retrieve the ball.
Thus, golf practice devices that attempt to help players improve their proficiency are well known in the art. Most of these devices are designed for use at home or at work. None of these practice devices are designed for use by the golfer near the hole that is about to be played i.e. is mobile so it can be used in the field of play prior to the golfer actually taking a shot. Thus, they cannot be set up so they are mobile to give a golfer the chance to practice under actual playing conditions with the club he or she is about to use.
For example, U.S. Pat. No. 2,929,632, issued to Moffatt shows a device for helping golfers practice their swing. The device has a hollow, golf-ball sized ball hung by a cord from one end of an L-shaped bar. The other end of the bar is firmly attached to the ground by a base plate that is anchored in the soil by two spikes on the bottom side of the plate. The Moffatt device provides a golfer with a device for practicing his or her stroke, but it is not mobile and can only be used in designated practice areas of a golf course. Golf courses limit the use of this device because of the holes the spikes create when they are pounded into the turf. Moreover, the device is cumbersome, and cannot be easily carried by a golfer from hole to hole during actual play.
While several patents have been issued on similar devices, none of these improved inventions can be used on the actual field of play. For example, UK Patent No. 1,263,269, issued to Hall discloses a mechanism which records and displays the number of times a struck ball rotates around the horizontal end of the L-shaped bar. Since the number of rotations is proportional to the club""s impact force against the ball, golfers are able to estimate the power in their stroke and the distance an untethered golf ball would travel. U.S. Pat. No. 4,932,660, issued to Wang discloses a rotatable and pivotable component. The Wang device has sensors in the component that can record both the angle and force with which the ball leaves the club head. A golfer can use the data provided by the Wang device to make more precise estimates on the force of the stroke and the direction in which a ball travels.
None of these golf practice devices allow golfers to practice their stroke under conditions which most closely resemble those of actual play. These devices do not permit golfers to practice their stroke from the approximate location where they must make a shot that counts in the game. Moreover, since these devices are located far from the actual course, golfers must forfeit the opportunity to practice their stroke just before they make the actual shot. Thus, it would be advantageous to have a golf practice device that is fully portable on a golf cart and allows golfers to practice their stroke by striking a golf ball and observing the motion of the ball, yet is proximate the shot being played thus, allowing a golfer to practice from the approximate location where they will make the shot on the course.
The present invention provides for a mobile golf practice device which attaches, either removably or fixedly, to a mobile golfing vehicle, such as an electric golf cart. In the broad aspect, a support shaft is mounted upon a golfing vehicle at its one end and rotationally attaches to tethered golf ball on the other such that the golf ball is in position over the ground to be struck as if the ball were in play. In one aspect of the invention, the device attaches to a bumper on a golf cart used to caddy players and equipment from hole to hole on the course.
The mobile practice device of the present invention comprises a vehicle attachment means for attaching the device to a vehicle; a support shaft having a first end and a second end with the first end adapted for fixed attachment to the attachment means; and, a golf ball tethering means rotationally attached proximate the second end of the shaft, for allowing the golf ball to orbit the shaft after being struck by the golf club.
The vehicle attachment means preferably comprises a plate, and mounting brackets attached to the plate. The mounting brackets are preferably designed to grip the top and bottom sides of a bumper in order to immovably fix the plate to the bumper. The gripping force of the brackets on the bumpers is adjusted by tightening or loosening threaded fasteners that attach the brackets to the plate. The threaded fasteners include screws, bolts, hexagonal nuts and wing nuts. This preferred vehicle attachment means eliminates the need for holes to be placed in the bumper.
In another preferred aspect, the vehicle attachment means comprises a C-clamp. The c-clamp has an adjustable tightening lip, and a holding lip facing opposite to the adjustable tightening lip. The vehicle attachment means is immovably attached to the golf cart bumper by tightening down the adjustable tightening lip onto the bumper. Similar to the mounting brackets described above, this preferred attachment means does not require holes to be drilled directly into the bumper.
In another aspect, the vehicle attachment means comprises a plate that is immovably fixed to the bumper of a golf cart by at least one fastener. The plate is preferably made from wood, rigid plastic, composite metal, or the like and more preferably, the plate is made from stainless steel or aluminum. The plate is preferably fastened to the golf cart bumper by pins, bolts, screws, or a combination of these fasteners, that are drilled directly into the bumper. The plate may also be adhesively attached to the bumper.
The support shaft is preferably bent at a substantially right angle, making a L-shaped, rigid shaft. In this preferred aspect, the first section of the shaft points substantially perpendicular to the ground, and the second section is aligned substantially parallel with the ground and in play position points away from the golf cart. The shaft is attached to the vehicle attachment means, proximate to the first section of the shaft, by any known means for attaching a shaft to a plate, including pins, screws and other fasteners, clamps, and retaining rings. In a preferred aspect, the shaft can be adjusted such that the second section points substantially away from the golf cart, while a golfer is practicing, and points substantially parallel with the golf cart, while the cart is in motion i.e. the shaft swivels from one fixed position to another for storage.
In another aspect, a strait, unbent shaft, having a first end and a second end opposite the first, is attached to the vehicle attachment means and the tethering means. In this preferred aspect, the long axis of the shaft is aligned substantially parallel to the ground. The shaft is attached to the vehicle attachment means, proximate to the first end of the shaft by any known means for attaching a shaft to a plate, including pins, screws and other fasteners, clamps, retaining rings, welds, adhesives, and mating threads between the shaft and the plate. The golf ball tethering means is attached to the unbent shaft, proximate to its second end.
The shaft, either L-shaped or unbent, can be solid or hollow, and can be made from a wide variety of rigid materials, including wood, composites, plastics, metals or the like. In a preferred aspect, the shaft is made from stainless steel, aluminum, or fiberglass.
The golf ball tethering means is preferably flexible but could be rigid. The flexible tethering means is for example, a flexible cord or braided wire having a lower end attached to the ball which is preferably the size of a standard golf ball, and an upper end rotationally attached to the shaft proximate the second end. Preferably the upper end of the tether if fixedly attached to an oblate spool or pulley which prevents the cord from wrapping around the shaft when it is struck and the spool or pulley is rotatably fastened to the horizontal end of the support shaft. In order for the spool to rotate freely on the end of the shaft, a bearing, fixed to the end of the shaft, for example is inserted in the center portion of the spool. In this fashion the inner diameter surface of the spool moves rotatably around the outer diameter surface of the fixed bearing with a minimum of friction.
In another preferred aspect, the flexible golf ball tethering means includes a rotatable member and a connecting bar that is attached to the member. The member is mounted on the shaft at approximately the horizontal end of the shaft and rotatable about the long axis of the shaft. The connecting bar has a first end swivelled on the rotatable member and a second end extending downwardly from the rotatable member, where the ball is attached to this second end. In this preferred aspect of the tethering means, when a golfer hits the ball with a club, the ball and connecting bar rotate and pivot about the shaft until the ball loses enough momentum to come to a complete stop.
In another aspect the flexible golf ball tethering means comprises a flexible cord attached to a unit formed from a pair of ring shaped grommets, connected together by a tubular sleeve. The grommets are rotatably inserted upon the shaft, proximate the horizontal end of the shaft, and the upper end of the flexible cord is tied around the tubular sleeve. In order to prevent the grommets from sliding across the shaft, or sliding off the end of the shaft, a first and a second laterally spaced retainer are affixed to the shaft on opposite ends of the grommets. In order for the grommets and tubular sleeve to rotate freely about the long axis of the shaft, a first and a second washer, encircling the shaft, are positioned on opposite ends of the grommets, with each washer sandwiched between the end of a grommet and one of the laterally spaced retainers.
In still another preferred aspect, the flexible golf ball tethering means includes a flexible cord or rope with an upper end and a lower end. The upper end of the cord is attached to the shaft at approximately the horizontal end, and the lower end of the shaft is attached to the ball. When the ball is struck, the ball orbits the long axis of the shaft until the cord has completely wrapped itself around the shaft.